- Written by John E. Johnson, Jr.
- Published on 16 October 2013
On the Bench
Distortion measurements were made within a 48 kHz bandwidth. The microphone was placed 1 foot from the speakers, except where noted, and pointed in between the respective pairs of drivers (tweeters, midrange, and woofers).
At 50 Hz (woofers), and 90 dB, distortion was only 0.34%.
At 20 Hz, distortion was at 10%, which is acceptable in some bench test arenas. It would be nice to have it closer to 5%, but really, full-range speakers just don't have the enclosure size to allow major deep bass output at low distortion. This is why a high quality (big) subwoofer is good to put in your audio system, even if you have full-range speakers like these.
At 5 kHz (midrange drivers), distortion was less than 0.5%, which is excellent performance.
And at 9 kHz (tweeters), there was only 0.33% THD+N.
The room frequency response was measured at 3 meters and 90 dB of white noise. The response was reasonably flat taking into account that there were room effects.
Impedance varied from a low of 2 ohms below 100 Hz to a high of 18 ohms at 3.9 kHz. Phase varied from + 500 to - 750, with the midrange frequencies having primarily inductive impedance and the low frequencies and high frequencies having primarily capacitive impedance (inductive and capacitive impedance are called reactive impedance, which occurs at all frequencies except 0 Hz, which is DC). Because the impedance was very low (2 ohms) when the phase was only - 200, the speaker would be judged a moderately easy load. However, the 2 ohm impedance in the < 100 Hz range would rule out using a low-end mass market receiver.
Overall, these are impressive bench test results.